﻿using System;
using System.IO;
using System.Security.Cryptography;
using System.Text;

namespace SalesSys.Comm.Utility
{
   public class EncryptEx
    {

        /// <summary>
        /// 获取md5 后的base64字符串,去除最后的 ==
        /// </summary>
        /// <param name="strText"></param>
        /// <param name="encoding"></param>
        /// <returns></returns>
        public static string MD5EncryptToBase64(string strText, Encoding encoding = null)
        {
            var result = Md5(strText, encoding);
            return Convert.ToBase64String(result).TrimEnd('=');
        }

       public static byte[] Md5(string strText, Encoding encoding)
       {
           encoding = encoding ?? Encoding.UTF8;
           MD5 md5 = new MD5CryptoServiceProvider();
           byte[] result = md5.ComputeHash(encoding.GetBytes(strText));
           return result;
       }

       public static string MD5ToString(string strText, Encoding encoding = null)
       {
           var output = Md5(strText, encoding);
          return  BitConverter.ToString(output).Replace("-", "");
       }

       private static byte[] Keys = { 0x12, 0x34, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF };
        
        /// <summary>
        /// DES加密字符串
        /// </summary>
        /// <param name="encryptString">待加密的字符串
        /// <param name="encryptKey">加密密钥,要求为8位
        /// <returns>加密成功返回加密后的字符串</returns>
        public static string EncryptDES(string encryptString, string encryptKey)
        {

                byte[] rgbKey = Encoding.UTF8.GetBytes(encryptKey.Substring(0, 8));
                byte[] rgbIV = Keys;
                byte[] inputByteArray = Encoding.UTF8.GetBytes(encryptString);
                DESCryptoServiceProvider dCSP = new DESCryptoServiceProvider();
                using (MemoryStream mStream = new MemoryStream())
                {
                    CryptoStream cStream = new CryptoStream(mStream, dCSP.CreateEncryptor(rgbKey, rgbIV), CryptoStreamMode.Write);
                    cStream.Write(inputByteArray, 0, inputByteArray.Length);
                    cStream.FlushFinalBlock();
                    return Convert.ToBase64String(mStream.ToArray());
                }
        }

        /// <summary>
        /// DES解密字符串
        /// </summary>
        /// <param name="decryptString">待解密的字符串
        /// <param name="decryptKey">解密密钥,要求为8位,和加密密钥相同
        /// <returns>解密成功返回解密后的字符串</returns>
        public static string DecryptDES(string decryptString, string decryptKey)
        {
            decryptString = decryptString.Replace(" ","+");

            byte[] rgbKey = Encoding.UTF8.GetBytes(decryptKey);
            byte[] rgbIV = Keys;
            byte[] inputByteArray = Convert.FromBase64String(decryptString);
            DESCryptoServiceProvider DCSP = new DESCryptoServiceProvider();
            using (MemoryStream mStream = new MemoryStream())
            {
                CryptoStream cStream = new CryptoStream(mStream, DCSP.CreateDecryptor(rgbKey, rgbIV), CryptoStreamMode.Write);
                cStream.Write(inputByteArray, 0, inputByteArray.Length);
                cStream.FlushFinalBlock();
                return Encoding.UTF8.GetString(mStream.ToArray());
            }
        }
    }
}
